Pilling Michael
MRC Institute of Hearing Research, Nottingham, United Kingdom.
J Speech Lang Hear Res. 2009 Aug;52(4):1073-81. doi: 10.1044/1092-4388(2009/07-0276).
It has recently been reported (e.g., V. van Wassenhove, K. W. Grant, & D. Poeppel, 2005) that audiovisual (AV) presented speech is associated with an N1/P2 auditory event-related potential (ERP) response that is lower in peak amplitude compared with the responses associated with auditory only (AO) speech. This effect was replicated. Further comparisons were made between ERP responses to AV speech in which the visual and auditory components were in or out of synchrony, to test whether the effect is associated with the operation of integration mechanisms, as has been claimed, or occurs because of other factors such as attention.
ERPs were recorded from participants presented with recordings of unimodal or AV speech syllables in a detection task.
Comparisons were made between AO and AV speech and between synchronous and asynchronous AV speech. Synchronous AV speech produced an N1/P2 with lower peak amplitudes than with AO speech, unaccounted for by linear superposition of visually evoked responses onto auditory-evoked responses. Asynchronous AV speech produced no amplitude reduction.
The dependence of N1/P2 amplitude reduction on AV synchrony validates it as an electrophysiological marker of AV integration.
最近有报道（例如，V. 范·瓦森霍夫、K. W. 格兰特和 D. 波佩尔，2005 年）指出，与仅听觉（AO）言语相关的反应相比，视听（AV）呈现的言语与峰值幅度较低的 N1/P2 听觉事件相关电位（ERP）反应有关。这种效应得到了重复验证。还对视觉和听觉成分同步或不同步的 AV 言语的 ERP 反应进行了进一步比较，以测试该效应是如所声称的那样与整合机制的运作相关，还是由于诸如注意力等其他因素而产生。
在检测任务中，从参与者那里记录他们对单峰或 AV 言语音节录音的 ERP。
对 AO 言语和 AV 言语之间以及同步和异步 AV 言语之间进行了比较。同步 AV 言语产生的 N1/P2 峰值幅度低于 AO 言语，视觉诱发反应在线性叠加到听觉诱发反应上无法解释这一现象。异步 AV 言语未产生幅度降低。
N1/P2 幅度降低对 AV 同步性的依赖性证实了它作为 AV 整合的电生理标志物的有效性。
